2a : Episode Seven : The Cause and the Cure
by Taidine
Summary: Jeremie has a new plan to cook up an antivirus for Aelita, but could this solution be more dangerous then the problem?  Part of an alternate lateseasontwo story arc.
1. Chapter 1 : Infection

**Episode Seven: The Cause and the Cure**

Soundtrack: Fallout Boy's "Dance, Dance" (Not because Yumi's cheating on Ulrich, because they're falling apart to half time)

_Yay! I'm back from my long haiatus and shall be wrapping up the story arc over the course of the next three weeks._

_This is probably my second favorite episode, for sheer cuteness factor. Another one that's more about advancing the plot then anything else, though… Also, took me longer to write then any of the others, seeing as I stopped after the first scene to take a prolonged break from Code Lyoko fanfics of any sort._

_Taidine_

Chapter One: Infection

It was early on a Saturday morning. The sun rose, bright and freshly washed from several days of dismal rain, over the sprawling campus of Kadic Academy. The few remaining leaves in the gardens gleamed with vibrant reds and yellows. Dew and persistent raindrops glistened on the grass of the green. Windows opened in dormitories, only to slam shut again when the sleepy students behind them felt the chill edge to the breeze.

Behind one window, a boy with spiky blonde hair and purple pajamas came awake to the sound of barking. A thick-bodied, sharp-faced dog was standing with four narrow paws planted firmly on his chest and yapping in his ear. "Oh, _Kiwi_," the boy said in a shrill, annoyed voice. "Okay! I'm getting up!"

The room's other occupant, another blonde boy with thick glasses and lousy fashion sense, glanced up from his laptop. By his hunched posture and sunken eyes, he had been sitting there all night. "It's about time, Odd," he told his roommate, "that dog's been barking for the last ten minutes."

Odd pushed back dog and covers with one sweep of his arm. Kiwi jumped onto the floor, stumpy tail pounding, and gave over barking in favor of licking his master's hand enthusiastically. "Good morning to you too, Jeremie," Odd said sarcastically, sitting up and rubbing his head.

"Thanks," said Jeremie, oblivious to his friend's tone. "When you get back from walking Kiwi, meet me in the cafeteria. I've got good news."

Odd shoved his feet into the shoes on the floor and groped under the bed for a leash. "You just saved a bunch of money on car insurance by switching to Geico?"

"No," said Jeremie, who didn't watch much television. "Better. I might have found the way to cure Aelita!"

- - - -

Twenty minutes later, a group of five had assembled outside the cafeteria. There was Odd, who had hidden Kiwi in his room and donned an outfit almost the same shade of purple as the swatch in his hair. There was Jeremie, looking sleep-deprived but exhilarated. The other three were a brown-haired, serious-faced boy, an Asian girl dressed in black, and a girl with shockingly pink hair and an expression almost as excited as Jeremie's.

"Ahem." Jeremie cleared his throat, a professor preparing for his lecture. "About two weeks ago, XANA attacked us using a modified flu virus." His 'students' nodded. "As we all know, we were saved by antibodies produced by Kiwi.

"Aelita-" a nod to the pink-haired girl "-has been infected by XANA with something similar: a computer virus that works on the same principals. Due to her origin in the Lyoko program, she's especially susceptible to the virus."

He beamed. Now for the best part. "However, since we _aren't _part of the Lyoko program, any of _us _can fight it off. Theoretically, this would create a kind of 'antibody' that could then be used to de-bug Aelita!"

Instead of the applause he had hoped for, there was stupefied silence. A pair of chatting girls skipped up the steps and vanished into the cafeteria. The sound of the door closing behind them seemed loud.

"Uh," said Odd finally, breaking the thunderous quiet, "You're going to infect one of _us _with Aelita's virus?"

Jeremie nodded.

"And this is going to _help_?"

"I'll do it," said the brown-haired boy, so far silent.

The girl next to him shook her head, twitching sleek black hair. "I don't think so, Ulrich. It sounds dangerous."

"Are you sure this will work, Jeremie?" Aelita asked.

"Absolutely," the bespectacled boy replied, "I ran several simulations. There's no reason any of us couldn't fight off your virus."

"I think he said that about the other antiviruses too…" Odd muttered.

"So I'll do it," Ulrich replied, ignoring the pessimistic comment. "When?"

"Well, I need some time to make sure I have a clean copy of the virus. Probably this evening."

"_Oh,_" said Odd in the tones of one who had just solved a difficult puzzle. "You don't want to go to the _dance. _Well, can't blame you, but you don't know what you'll be missing. I spent the whole weekend downloading songs from the Internet and burning my party mix…"

Ulrich looked uneasily at the black-haired girl to his right, who was staring at him with an accusatory expression, and cut off his friend's babbling. "The dance is tonight?"

She nodded.

"Oh… I'm sorry, Yumi, but…"

"I understand," she said tersely, and maybe she did, but she didn't sound happy about it. "Stopping XANA is more important then some- school function. I'll go with you."

In the distance, a bell shrilled. "So… meet you at the Factory," said Jeremie quickly, and the five pounded off to their classes.

- - - -

Odd dozed.

The math teacher was droning about quadrilateral equations or something, but in his mind, the spiky-haired boy was already at tonight's dance. First he would slip the DJ his party mix, then slide out across the floor solo, partner up with Sissi for a few numbers… no, this was his fantasy. Every girl in the school would decide to talk to him again, including that hot blonde who sat in front of him during science, and he would dance until he was exhausted. Mind as well enjoy it now. Thanks to Jeremie's latest brainstorm, he wouldn't be going to the dance. The whole gang would be at the Factory – just in case.

The shrill jangle of the bell interrupted Mrs. Meyer mid-drone and woke Odd from his reverie. His former lethargy was belied by the speed with which he shoved a notebook in his backpack and darted for the door.

Odd had broken several unofficial 'doorway sprint' records in his time. This probably didn't make his top ten, but it did get him out of the classroom before the remainder of the students hit the bottleneck of the doorway. He walked several steps down the hall, then squeezed himself into a nook on the lee side of a water fountain as the mass entity of the Crowd surged past.

In a few minutes, he was joined by Ulrich, looking grim and serious. This might have been due to his upcoming ordeal, or possibly the quadratic equations. "Ready?" asked Odd, leading the way back into the milling hallway.

The majority of the students streamed towards their dormitories to prep for the dance. This sort of thing only came around once a season; it was an Occasion. Ulrich and Odd broke paths with them as they walked along the green, making instead for the barely-tamed trees of the school gardens.

The noise of the students fell away as they entered the wood. Long shadows cast by the setting sun barred the forest floor, obscuring sight, and the chill of winter in the air was enough to make Odd shiver, although Ulrich stoically ignored it.

"Odd? Ulrich? Is that you?" breathed a figure obscured by the heavy contrast of light and dark. A glint of pink identified her – Aelita, walking towards them, with Jeremie trailing close behind.

There was a pause as Odd tried to think of a witty retort. "No, it's-" he began.

"Yes," Ulrich interrupted.

Odd shot him a glance and the four resumed walking. "Where's Yumi?" Ulrich announced after a few moments passed, silent except for the crunching of leaves underfoot.

Jeremie shrugged. "She said she had to go home and make up an excuse. She'll meet us at the Factory."

Ulrich's brows drew together, and his stride lengthened. He reached the hatch before the others, pulled it open, and dropped down the shaft, all without speaking.

"Great. Just great." Odd summed up the feelings of the remaining three before following.

Two skateboards and two scooters rattled through the dark tunnel, flickering through shafts of light that faded even as the four traveled. By the time they reached the Factory, the sun had dropped below the horizon and the last dregs of light were draining away.

The doors of the elevator clicked and rotated, intricate locks disengaging. Jeremie stepped out into the industrial jungle of the computer room, glasses bright with fluorescent reflections. "Aelita, come with me. You might be able to help with the programming. Ulrich, get down to the scanner room."

"What about me?" Protested Odd shrilly.

"Uh… I hadn't thought of that." Jeremie made his brisk way across the room, footsteps echoing in the cavernous space, and sat down in the computer chair. Aelita took up a position behind him, one hand on the headrest. Odd shrugged and stepped out of the elevator, leaving Ulrich alone as the doors hissed shut.

- - - -

In the tunnel that led to the Factory, Yumi grabbed the final skateboard and tossed it to the floor, black clothes and dark hair merging with the shadows so only the pale oval of her face was clear in the spitting, inconsistent illumination of the fluorescent bulbs set into the walls. A flashlight dangled from her wrist, switched off. Although the lights spaced along the tunnel were fitful and ill kept, she knew this stretch of sewer well enough to run it in the dark. She kicked off smoothly with one foot, sending her skateboard rattling along the tunnel.

Light-dark-light-dark. Incandescent light made her face and hands unnaturally pale. Light-dark-dark. She passed a set of burnt out bulbs. Light-dark-light. Ahead, a shaft rose into the darkness, striped with the bars of a built-in ladder. Yumi turned her board and skidded to a stop next to a pair of scooters, kicking back to flip the front end up and leaping off before the sparks had died. She caught the tip and leaned it casually against the wall before grabbing a rung of the ladder and climbing up hand over hand.

This side, the hatch opened to a heavy shove. Yumi's fingers dug into the long handhold and, bracing herself with an arm jammed between a ladder rung, shoved the heavy metal disk to one side. Lithe as a panther, the girl scrambled through the resulting gap to lie, panting, in the grass.

The lights from the city across the river were too dim to do more then define shadows, but by their dirty glow the hulking silhouette of the Factory and the spidery shape of the bridge leading to it could be distinguished. Yumi squinted. Was that a flicker of movement at the base of one slender pylon?

Rising into a wary crouch, she aimed her flashlight like a gun. She didn't want to get into trouble if she could avoid it, but there _was _someone, now a smudge against the city lights, now a glimmer in the dark, and that someone was moving right towards her. Even with the dim lights from across the river and the paltry illumination of a crescent moon, they couldn't miss her… or the hatch…

Her heart thudded against her ribs. It was one thing to sneak around school grounds hiding from monsters. Out here she felt like a criminal. She didn't have an excuse; she didn't even have a plan. All she had was desperation.

The figure was nearly on top of her now, its goal obviously herself or the hatch she guarded. She adjusted the aim of her flashlight and flicked it abruptly on.

Yumi only got one glimpse of the person's face, shocked and staring like a deer in the headlights, a brief glimpse before she flicked off the device, yanked the hatch cover shut and took off for the bridge, trusting the temporary blindness brought on by sudden, bright light to hide her. That glimpse was enough.

- - - -

Numbers flickered across the computer screen, captivating Jeremie's attention; a human figure slowly filling with green held the gaze of Aelita and Odd. A small notation in the corner flicked up to 20.

"Mmm?" Jeremie made a small noise, tilting his head.

"What is it?" Aelita asked, instantly transferring her attention to the numbers. Some of it was comprehensible, but she wasn't as fluent in it as Jeremie; her knowledge was the more intuitive sort.

"I thought I saw something I took out," he answered, hand hovering over the 'esc' key. "Maybe I should…"

"If you took it out, it's not there. Relax, Einstein," Odd advised. Aelita nodded her cautious agreement.

Jeremie kept watching, then gave a little sigh of relief. "Never mind. The secondary loop was gone, and I couldn't have taken it out without disabling… uh, we're good. I mean, unless someone put it back _in._" He smiled at the ridiculousness of the idea, then resumed his intent study of the dancing numbers.

There was a click, and the elevator doors opened. Yumi stumbled out, panting slightly, and sat heavily on one of the metal protrusions emerging from the floor.

"Yumi," Aelita greeted. Jeremie didn't even look up. "Is something wrong?"

"Probably not," said the black-haired girl, inhaling deeply. "But… is there any reason for _William _to be hanging around the Factory?"


	2. Chapter 2 : Prognosis

**Episode Seven: The Cause and the Cure**

Soundtrack: Fallout Boy's "Dance, Dance" (Not because Yumi's cheating on Ulrich, because they're falling apart to half time)

Chapter Two: Prognosis

Back at the school, only one classroom remained occupied as the sun dropped beneath the horizon – an English classroom on the second floor. Within, a bevy of students frantically pieced together the latest edition of the Kadic Herald. One senior staff member manned the computer, typing like a madwoman as writers turned in articles. At the desks, arranged in scattered islands, further reporters scribbled in longhand and swapped papers for proofreading or ideas.

At the table closest to the door, a boy with messy brown hair leaned over the shoulder of a dark-complected girl chewing on her pencil. "Tamia!" He said loudly over the buzz of the newsroom, "We have half an hour before the dance! Let's just go, Kloe isn't _that_ scary."

Tamia sigh, tucking a cornrow braid behind her ear. "I couldn't care less about the editor. I just don't want to be trying to finish this Saturday morning. Do you know any good jokes?"

The boy dropped into the chair next to her, propped his feet on the desk, and glanced sidelong at his friend. "How about… why did the Kloe cross the road?"

"Theo, be serious. I want to be out of here before midnight."

"She was investigating the chicken!" Theo seemed to find this greatly amusing, leaning is head back on his chair with an enormous grin.

He found himself staring at the upside-down face of a tall, blonde girl with a slim choker encircling her neck. "It was actually a pigeon working undercover to break up a seedy black-market trade in counterfeit eggs," the editor of the Kadic Weekly said tartly. "Tamia, are you done?"

"Um… I have a couple. I thought if we stick it under the movie reviews…" Tamia began, a touch sheepish.

"Perfect," Kloe interrupted. "I know you're not going to get any more done with him here, anyway-" she rapped Theo on the head with her pen, provoking a small, disingenuous 'ouch' "-so why don't we call it a day?"

The tyrannical editor tucked her pen behind one ear, where it nestled snugly among her short, choppy locks, and turned her attention to the room at large. "Hear that, everyone? Wrap it up! I'm running what we've got tomorrow, because this room closes in five minutes!" Technically, this was the prerogative of their teacher, but as usual, he was absent from the newspaper meeting.

To the vast relief of Theo and Tamia, Kloe slouched off to bother someone else – namely, the small redhead typing furiously at the room's sole computer. "Millie? Can you finish in five minutes?"

"Maybe," squeaked the girl in a high-pitched voice. "You could have asked me before making that announcement, you know."

"Yeah. Sorry, I've got a dance to go to," Kloe explained.

"You don't even have a date," Millie pointed out with the offhand knowledge of gossip only a true reporter can achieve.

"Mmm," Kloe agreed, looking at the clock on the wall. "and I've got half an hour to find one. Tell you what, how about you shut the lights?"

"Sure," squeaked Millie, who had, after all, been in the business long before Kloe had arrived at Kadic. Once she got over her initial awe of the new editor's audacity, she had begun to feel snubbed at the way her own authority was usurped. That might have been why Kloe was gradually handing her more power as time went on; or that might be giving the editor too much credit.

At any rate, Kloe wasn't exactly glowing with pride and happiness as she stalked out of the newsroom. This dance had been a sticking point for days and she hadn't even brought it up with a boy. Truth was, she hadn't met a boy yet who seemed to like her, and she couldn't imagine why. _Unless my charming personality puts them off, _she needled herself. All right, so she was abrasive. And insensitive. And enjoyed dancing verbal circles around people, even if it meant making up words. And maybe she could be a little condescending, too. If she read more romance novels, she might have believed the right boy could get past all that.

_I wonder if Jeremie… _Hah. Funny. The geek in glasses would be going out with Miss Pink Hair. Which wasn't, by any means, why Kloe was annoyed by Aelita – any genuine dislike of the girl was sparse, and stemmed from a combination of not-so-politely rejected interviews (in full possession of her memories, Kloe began to understand why Aelita didn't want to talk about her pre-Kadic life; 'I grew up in a program in a supercomputer' is hardly a good answer to any question) and the vague, irksome feeling that Aelita thought the newspaper was a bit of a joke. Come to think of it, Kloe wasn't even sure she herself liked Jeremie, although the idea had been simmering on the backburners of her mind for weeks. 'Smartest kid in school' didn't mean he could hold an intelligent conversation, and while the fact that he saved the world on a regular basis was appealing, and she couldn't resist a boy who knew C++, she worried it was more a conquest thing then anything else.

So no Jeremie. Who did that leave?

By this time Kloe had made her way down the stairs to the first floor and out the doors of the main building. As she headed for the dormitories, deep in thought, a figure passing the front of the school was suddenly bathed in the glow of a single external bulb like a rock star in a spotlight. Tousled black hair, dark clothes, meltingly handsome features… _Oh, shades. _"Hey, William," she called out, stringently keeping her cool.

For a bare instant, he looked nonplussed, even frightened. His eyes darted towards her, and recognition relaxed him so quickly she might have imagined it. "Hey, Kloe," he responded, casual and smooth.

She had to ask. How could she not? It was too fortuitous, almost contrived. "So… headed for the dance? Who's the lucky girl?"

"Mm… actually, I was going solo."

_Don't appear to eager, _Kloe admonished herself. This was the date every girl in the school was chivying for, which on its own would have been reason enough to walk away if William hadn't fallen in alongside her, the fluorescent lights causing a halo to outline his profile. "Funny, me too. It's kind of rough, you know, I feel like I should at least walk in with someone. Hey, maybe we could…" she let it dangle.

They had reached the dormitories. He glanced over at her, his look almost calculating, but apparently took the hint. "Um… okay. Tell you what, I'll, uh – meet you out here in ten?"

"Sure." Kloe answered, cheering silently.

A few minutes later, in her own room, changing, she looked back on the episode and wondered what she had been thinking. William had that effect on people.

- - - -

"Maybe it wasn't William," Yumi acceded as the five parked scooters and skateboards. Odd scrambled up the ladder like a monkey to push open the hatch on the school side. There was a silence, broken only by the scrape of metal, as the others followed and climbed out into the star-sprinkled night. Ulrich brushed past Yumi, who grabbed his hand.

"Hey. You sure you're okay?" she asked. She would never admit it, but she didn't like the idea of this virus. What if Jeremie hadn't pulled all of its teeth?

Ulrich firmly disengaged her pale fingers. "I'd be a lot better if you stopped talking about William," he responded. It might have been a joke, but you never could tell, with Ulrich.

After that, there was really nothing to say. The walk back to the dorms was heavy with enforced silence and things left unspoken.

- - - -

In the cafeteria, on the other hand, it was quite noisy. For Odd, the relaxed atmosphere came as a tremendous relief. Only the earliest arrivals were present, chatting as they set up food and decorations. A pair of long lunch tables were pushed against one wall, laden with chips and drinks; the others had been tucked away, replaced by a scattering of folding chairs and the wide space of the dance floor which Odd was striding across.

The spiky-haired boy wasn't dressed up. Why bother? His purple-on-purple would blend well enough with the eclectic costumes of a student dance. Instead of wasting time changing, he had come straight here to chat with tonight's DJ, a boy with a pair of ubiquitous headphones one grade closer to escaping this school for good.

"…Sean Paul, most of the classics, and Crazy Frog. Now that's techno!" Odd was saying, handing over a pair of discs.

"What, no Cascada?" the DJ asked in a voice that would have been deep even when not juxtaposed against Odd's nasal shrill.

The first wave of students were arriving, with Ulrich and Yumi trailing them. The pair must have made some sort of peace, because they were clearly coming in _together_. They certainly hadn't wasted time on outfits; Ulrich's hair was neatly combed, and Yumi had donned black pants so voluminous they could pass for a skirt when she stood still, but that was their only concession to formality.

"Cascada?!" Odd exclaimed indignantly, "but all of their songs sound the same!" He wasn't devoting all of his attention to the argument; it was much more interesting to watch further students promenade in. Was that Kloe in a halter top – with William? Interesting. And he would have to ask Xavier where he got his hats, this latest one was very… purple.

"No way," the DJ insisted. "They recycle the beat, but you've got to listen to the instrumentals." He was watching the arriving students as well. "Hey, man, who's the chick?"

It was Sissi.

For a moment, Odd didn't recognize her; she looked more like she was heading for the prom then a fall dance. A bright orange dress clung to her body, making her look curvy rather then, as he had always thought, slightly plump, and dropped to a full skirt around her knees. That awful yellow headband had been discarded in favor of an orange scrunchy pulling her hair back into a high ponytail. The makeup was still overdone but – this was strange – she had used a black pencil, or maybe liquid eyeliner, to paint a spiral radiating outward from each eye and curling over her temples in eerie imitation of her Lyoko character's tattoos.

She couldn't remember that, though.

Could she?

"Huh," said Odd, then, "Actually, she's with me. Well, have fun with the mix, I spent a long time on that." Without further comment, he ducked around the DJ's table and headed for the door.

"Care to dance?" He invited, holding out a hand to Sissi.

Jeremie and Aelita swept past, the former in a button-up shirt and tie, the latter in a dress of green-sashed pink, ragged, two-tiered hemline brushing the floor. Odd was peripherally aware of Jeremie tucking his laptop away under a folding chair before the music started in earnest and Sissi accepted his hand. Turned out she _was_ a more then halfway decent dancer.

- - - -

It wasn't until Odd excused himself to have a word with the DJ and Sissi plopped herself down in a chair against the wall that she realized she hadn't thought about dancing with Ulrich all evening. Funny, that, since this was all a finely calculated ploy to elicit his jealousy. And maybe a little bit because Odd had saved her life, but they didn't know she knew that, did they?

_Beep. Beep. Beep. _Something chirruped quietly from under her seat.

"Hmm?" With a small noise of inquiry, Sissi rose and peered between the legs of her folding chair. There appeared to be an austere silver laptop resting there, closed but not silenced. Never shy with the handling of other people's property, Sissi pulled it out and placed it atop the chair. Then, sitting in front of it with her skirts spread out around her like some tropical flower, she opened the noisy device.

Displayed on the screen was a thin, translucent cylinder wreathed in malevolent-looking mist.

Sissi's eyes darted around the screen. _Beep. Beep. Beep. _There was something that read 'desert sector,' incomprehensible code, and, in one corner, a symbol of three consecutive circles that she recognized with a chill.

The principal's daughter stood and smoothed her skirts, sweeping her gaze across the dark cafeteria. She needed to find Odd. Or Jeremie. Or –

"Looking for someone, Sissi?" asked a voice by her elbow.

She spun around, loose skirt flaring. "Ulrich!" No endearment followed, a measure of how flustered she felt. "Jeremie's laptop… I think XANA's attacking!"

Ulrich laughed, closing the laptop with one hand. "Nah, Jeremie's running some diagnostics. Wanna dance?"

"Huh?" It was the invitation Sissi had despaired of ever getting. " Mm – of course!"

He grasped her hand and wound an arm around her waist. _Not as graceful as Odd, _she found herself thinking. But this was _Ulrich. _No Yumi. No questions.

Wait.

Ulrich thought she didn't know about XANA or Lyoko. Why had he been so accepting?

Although every romantic cell in her body protested, she managed to pull herself free from her partner. Come to think of it, this wasn't really a partner dance. "No! You're not… where's Yumi?" She couldn't believe she was asking.

"Getting a drink," Ulrich temporized, trying to catch up her hand again.

"Let me go!" Sissi shrieked. Something alien flickered in Ulrich's eyes. She backed away, heedless of the crowds, and banged into something. A wall? No, a door, the handle digging into the small of her back.

"Sissi, there's nothing wrong. Why are you-"

She managed to wrap her fingers around the handle and twist it. The door opened, spilling her backwards onto the steps.

"…and beat that level by – huh?"

There were two people sitting on the broad stoop of the cafeteria. Jeremie had taken off his tie, but that didn't help the dreadfully antiquated button-up, collared shirt; Aelita, in pink and green, looked like a watermelon. Sissi had never been so happy to see them.

"Jeremie!" Sissi shrilled, "Your laptop was beeping and XANA's activated a Tower and I think something's wrong with Ulrich!"

The boy blinked owlishly through his glasses. "Wait. How do you know about-"

"Does it really matter?" Sissi interrupted primly, "I'll tell you, but we need to get to the Factory."

"I… let me get my laptop," said Jeremie suspiciously.

"If XANA is attacking, we have to act quickly," Aelita disagreed, rising to her feet. Without warning, the girl reached out, clasping Sissi's head in both hands and turning her so the principal's daughter was forced to stare into her eyes. "I don't see anything – and I can't imagine why XANA would want to lure us _to _the Factory."

"Hey!" Sissi protested indignantly, pulling free, "I just warned you about everyone being in danger and you try to – to – what were you trying to do, anyway?"

Jeremie ignored her. "All right. Sissi, get everyone else. Aelita and I will go. But how-"

"Kloe fixed the thing that goes back in time," said Sissi briskly, "But what about Ulrich?"

- - - -

Back in the heavy, dark ambience of the cafeteria, Kloe sat down near the snack table, feeling her feet vibrate to the pounding music. Her peach halter-top clung to the sweat on her back, and she was wishing she had worn a skirt instead of her loose white pants; dancing was hot work, and William was a good partner. Of course, she'd paired off with some other boys, Theo, most of the male newsroom staff, and one of the boys from Sissi's gang who seemed lost without his mistress. Herve, if her memory didn't fail her – clumsy, in a charming way. Now, where had William got to? She sipped a cup of fruit punch idly, studying the room. There he was, near the back, chatting with – Ulrich? Since when were they friends?

"Psst – Kloe!" A shrill voice hissed in her ear.

"Sissi?" She answered quizzically, turning her head. The principal's daughter was standing behind her with a furtive air.

"See Ulrich and William there?"

"Yeah…" said Kloe, trying to figure out where this was going.

"Can you see Yumi?" Sissi continued.

Now Kloe's confusion had a more familiar form. "She's near the back wall, closer to us, looking irritated. Look, I'm not getting involved in a scheme to break up a love triangle, so why don't you get Herve and Nicolas to-"

"Shh!" Sissi cut her off, "They're moving towards the doors! We have to go!"

Grabbing Kloe's hand, she darted for the cafeteria exit in a cloud of cloying perfume.


	3. Chapter 3 : The Best Medicine

**Episode Seven: The Cause and the Cure**

Soundtrack: Fallout Boy's "Dance, Dance" (Not because Yumi's cheating on Ulrich, because they're falling apart to half time)

Chapter Three: The Best Medicine

_Hi. I want to apologize for updates being horribly inconsistent. Summer homework plus a spotty internet connection plus working on an original novel will do that, and it's not likely to get better any time soon. So, for the... one? Two? people reading this regularly, I'm sorry._

_Taidine_

"I'd be going slower on a skateboard, trust me," Kloe assured Jeremie, jogging along beside his scooter.

"Uh-huh," Jeremie agreed, "So… you said you would explain?"

"Sure," Kloe answered, panting slightly. Stupid strappy sandals. "It all started with the policewoman. First time you sent me into Lyoko? I could remember it if someone reminded me."

"That was when the return-to-the-past program first started to malfunction," Aelita offered, scootering smoothly despite the hindrance of skirts.

"Sure," said Kloe. "Anyway, even when no one reminded me, I was suspicious. So I started following you to the Factory. Coming down mornings, copying code, stuff like that, trying to figure out what was going on. Then I accidentally got some security programming, so I tried to get myself into it…"

"Wait," Jeremie interrupted, "_You _reprogrammed the return-to-the-past program?"

"No, I've got a cousin in Italy. Amazing programmer. I sent her all the code – by mail, mostly, in thumbnail drives. What's with the big secret deal, anyway?"

"Well. We could stop XANA at any time by turning off the supercomputer, but that would kill Aelita. Anyone else who found out probably wouldn't care." Jeremie explained briefly.

"But you think you can save everyone, including her," Kloe finished for him. "Fair enough. Look, Sissi and I haven't told anyone, and we've known for weeks. I think you can trust us." _And it's probably too late to do anything about it, anyway. How far back in time can you go, Jeremie?_

"Right. Uh – why Sissi?" Jeremie couldn't stem his curiosity.

"She couldn't. Have done it. Without me." Sissi panted, lagging behind.

"Apparently, Elizabeth can pick locks. Scary thought," Kloe needled deliberately, more then a little short of breath herself. Fortunately, the exit had become visible before them.

Jeremie went first to push open the hatch. The only response Kloe's comment elicited was a disgruntled, "_Sis_-si," so she tried again. "Can we talk about Ulrich? Why'd he go psycho?"

"I think he's being possessed by XANA," Jeremie said, giving Aelita a hand up.

"That shouldn't be possible," said the pink-haired girl.

"Because he's used to fighting on Lyoko. Right," said Jeremie. Kloe emerged from the hatch – no helping hand for her – and paused a moment while Sissi caught up. "But you're virus, Aelita, might have created a… gap in his defenses. I still think he can fight it off, but I'm not trusting our lives to it." He led the way over the bridge.

"What will he do? Will he come after us?" Asked Sissi.

"Probably not," answered Jeremie, feeling his way across the bridge in the dark. "XANA wants Aelita in Lyoko – alone. More likely it will focus on Yumi and Odd."

"I hope you're right," Kloe muttered darkly. She had few illusions as to her fighting abilities. One on one with Ulrich, athlete of the month? She'd probably wind up dead.

- - - -

Yumi shoved her way through the crowded cafeteria, liberally employing heels and elbows in a grim, smoldering rage.

"Ulrich!"

The brown-haired boy, deep in conversation with William (what was that about, anyway?) looked back over his shoulder. "Yumi."

She grabbed his shoulders and turned him around. "You danced with Sissi. You danced with Sissi!"

"Uh." He lowered his eyes. "Yeah, I'm sorry, it's just…"

"Sorry?" She asked, suddenly saccharine. "What is there to be sorry about? I'm not going to…"

He looked up, perhaps confused by her turbulent moods. Flickering in his eyes where there should have been pupils were a pair of symbols – three concentric rings…

Yumi's own eyes widened in shock. "No…" Hissed out from between her tight lips. Before Ulrich – before _XANA_ – could stop her, she darted away towards the tape deck.

"Odd!" The spiky-haired boy looked up at his name shouted breathlessly.

"Yes, that would be me," he said slowly.

Yumi skidded to a panting halt. "Odd, we have to get out. XANA is possessing Ulrich!"

"Is he now?" Maintaining a casual façade for the benefit of the DJ, sitting behind a magazine nearby, Odd lifted his gaze over the crowd of oblivious students.

Ulrich was standing by the door, staring straight at Odd and Yumi with a smile that clearly said, _too late. _One hand rose, fingertips subtly flickering; Yumi ducked instinctively as the tape deck lit with a mass of blue sparks. "Huh?" Odd had time for a small noise of surprise and a quick glace at his hand, resting atop the archaic sound system – but not enough time to pull his hand away. Vivid flashed of electricity leapt up around him, then vanished, and he slumped to the ground.

Yumi touched two fingers to her friend's neck. There was still a pulse, to her great relief.

"Hey, man," the DJ said, glancing up from his magazine, "the wacko Crazy Frog fan okay?"

"He's fine," Yumi said brusquely, "I'll go get some water for him."

The DJ had vanished behind his magazine before she finished talking.

- - - -

Kloe stepped into the scanner with a grin that was more then a little smug. "Scanner, Aelita. Scanner, Sissi. Scanner, Kloe," said Jeremie. He sounded grudging, but between Sissi's threats and Kloe's reasonable suggestion that they could serve as meat shields if nothing else, he had sent the two outsiders down to be virtualized. She suspected he would start scheming to get rid of them as soon as this crisis was over, but for now…

The doors clanked shut, sealing her in the smooth golden cylinder. Creamy light flared beneath her, accompanied by an updraft that made her jagged blonde hair stand on end.

"Transfer, Aelita." The pink-haired girl closed her eyes and tilted back her head. "Transfer, Sissi." The black hair of the principal's daughter had escaped its scrunchy and rose like sooty seaweed in the artificial wind while her orange dress swirled and billowed about her ankles. "Transfer, Kloe."

She shut her eyes. There was a flash of black, shot through with red, and a disoriented motion replaced the usual sensations of limbs and gravity. For a fleeting, nauseating second she was nothing but a disembodied consciousness.

"Virtualization." Jeremie's calm, satisfied voice caused a feeling of warmth to well up under her panic before the numb pain of being slammed together out of numbers and code put a halt to all thought.

- - - -

The sterile, golden landscape of the desert sector was motionless, here. From a landscape predominantly flat as steamrolled play-dough, a trio of sandstone spars rose up into the featureless sky. Below them, the landscape dropped away vertiginously, ending in the syrup-golden waters of the virtual sea. Above the peak of the highest spire, three humanoid figures phased into existence. Color spilled over their silhouettes like paint, and one after another they dropped to the ground: Aelita, lithe and pointy-eared; Kloe, in a crimson-and-gold coat that would have suited a soldier of the British empire; and Sissi, in clinging, sequined black, trailing a diaphanous pink scarf behind her.

Aelita landed gracefully, crouching to absorb the shock. Kloe landed on her stomach, as usual. Sissi, anticipating the drop, managed to keep her feet under her, but found herself teetering on the edge of a long, long drop.

With a tiny squeak, she jumped backwards, stepping on Kloe's hand. The reporter swatted her ankle, where a pink legwarmer dropped towards a black shoe. Sissi pivoted, flaring up at the other girl. "What are you trying to do, kill me?"

"You're, apparently, trying to crush my fingers. And I could push you over the edge all I like; it's not as if you'd _die_," Kloe retorted scathingly, struggling to her feet.

"What do you know, anyway?" Sissi countered shrilly, "That's the Digital-" what had Odd called it? "Ocean, and you can't devirtualize if you fall into it, so there."

"Ahem," Jeremie interrupted, "The Tower is to your right. I didn't think it was safe to put you down any closer."

The three girls turned with almost perfect synchronization to the right. A long, slender arch sprung out from the spire they were standing on some yards below, connecting it to a squatter stone pinnacle; scarcely visible from here, a ridge circled that other spire, twisting from the middle, where the land bridge connected, to the top. It looked about wide enough to walk up in single file, and met its terminus at a comparatively short, pale cylinder wreathed in red mist.

Kloe spoke for all of them with a simple, deeply sarcastic, "Nice."

"I think we can make it," said Aelita, "At least XANA's monsters will only be able to attack one at a time."

"Until they push us off the edge," Sissi added sourly.

"Then hurry up!" Jeremie suggested sensibly.

Aelita sat on the edge of the plateau, swung her feet into empty air above the narrow path, and dropped. The thin line of land seemed a narrow barrier between herself and the dizzying drop. Sissi grit her teeth, got a running start, and leapt over the edge, pink scarf trailing out behind her in a double loop from where it cinched at her wrists and neck. She touched ground gracefully in front of the elf girl. Kloe dropped off the edge as Aelita had, less certain of her virtual character's coordination, and won herself the position of rearguard.

Jeremie, safely ensconced in his computer chair, studied the screen with an air of solemnity. Kloe and Sissi – he didn't trust those two. Letting anyone else into Lyoko had been a mistake, and trusting them with Aelita's life doubly so.

With that thought, he brought up the materialization program on a secondary screen and started it loading. Aelita was the most important of all of them, to the world as much as to Jeremie himself. If anything untoward happened, he wanted to be able to pull her out.

When he looked back at the map, several red triangles had flicked into existence at perhaps the halfway point of the impossibly elongated bridge. He pushed his earpiece a little closer to his mouth. "Trouble ahead."

- - - -

Yumi clung to the wall, trying to evade the gaze of Ulrich. He didn't seem to be looking for her anymore; he had taken a casual stance near one side of the cafeteria double doors. She wasn't fooled; the instant she tried to open one of those doors, he'd be on her like a cat on a mouse. If he spotted her at all, in fact. This wasn't her friend, this was XANA.

Unbelievably, the dance was continuing all around her. The DJ had put on a Cascada album and 'Every Time we Touch' was winding down to an end. Across the dance floor, pairs of students spun and dipped. The cheap mobile disco ball resting on the floor rotated slowly, the colored lights it cast tracing lazy circles on the walls. The darkness and noise parted and flowed around her, too unrelated, surreal.

A messy-haired figure in black had cut through the crowd to chat with Yumi's possessed friend. _William? _Yumi shoved back the mix of emotion she felt towards the boy. _Figure it out, William. Something's wrong with him… _Why was William talking to Ulrich, anyway? Weren't they bitter rivals? _It doesn't matter. He just needs to provide a distraction. _A haunting image of William, caught blinking in the beam of her flashlight up by the Factory, rose up in her mind. Hadn't he walked in with Kloe? A quick glance couldn't locate the blonde reporter anywhere.

William slipped past Ulrich and out the doors with a friendly wave. Maybe XANA wasn't keeping people in. At any rate, this was as good a chance as Yumi was going to get. She pursed her lips and darted for the door.

She managed to touch the doorknob before a pair of hands grabbed her shoulders with preternatural strength and turned her around. She found herself staring into a pair of eyes pupilled with XANA's symbol. "Wanna dance?" Ulrich asked as a new song began to play over the cheap speakers.

Yumi tried to tear free, but she and Ulrich were evenly matched even without XANA's possession boosting his natural abilities. "Let go of me!" Yumi commanded harshly.

Ulrich gave an unpleasant laugh. "Hardly. Your friend Jeremie's given me a unique opportunity and I don't plan to squander it." The words were alien in Ulrich's familiar voice, undistorted by the echoing vocal affects that usually accompanied XANA's speech.

"The virus?" Yumi asked. He was leading her onto the dance floor, holding her hand and waist in a vise-like grip.

"Of course." It wasn't really Ulrich speaking, she reminded herself.

"But-" she began. _But Jeremie said Ulrich should be able to fight the virus off, so maybe there's a chance._

"But nothing," Ulrich – or rather, XANA – responded. "Those fools in Lyoko won't be able to hold Aelita back this time. And as for you…" In a carefully timed spin, Yumi found herself pressed up against the wall. The raised square of a power outlet dug into the back of her leg.

Yumi squeezed Ulrich's hand, staring into eyes marred by XANA's concentric-circles symbol. "Ulrich," she pleaded, feeling the tickle of static building in the outlet, "don't let him do this."

For a second, the symbol flickered. Ulrich threw her aside as a tongue of blue sparks leapt from the outlet. Then he jerked her closer, eyes once again betraying his possession. "I see. Your friend's quite strong-willed, but not a match for me."

They were straying towards a speaker now, but that flicker of hope had been fanned.

- - - -

Sissi lead the way, fuming at Kloe and Jeremie and all the rest of Ulrich's insufferable gang for various reasons, but mostly because it was their fault her life was in actual, real danger, when the monsters appeared. They made no sound, merely materialized from the air, gridded, then clothed in a rusty red color. She didn't immediately recognize the type, catching merely a confused impression of domed shells and long, segmented legs as they fell to the ground.

"Krabes," said Jeremie, "Not too powerful, but quick."

A moment of concentration, and a faint pink glow sprung up around Sissi's hands as she clenched them into fists. Kloe unsheathed a dart.

The krabs fired first. There were two of them, small change, but their lasers came perilously close. Sissi jumped for the dome of the first, pulled herself gracefully atop it, and jammed one fist against the symbol of XANA at its center. The pink aura wreathing her hand flared, and the monster collapsed in a pile of cogs and gears. The one behind her managed to score two hits, leaving her shoulder and side shot briefly with blue sparks, before a well-aimed dart from Kloe took out its single, malevolent eye and Sissi managed to grab its gun turret. Kloe's second shot struck home, dispatching the beast.

"Cake," Kloe panted, dusting imaginary dirt off her uniform.

"That won't be all," Aelita warned, beginning to walk again. Sissi was forced to move forward or risk being pushed over a side. "Jeremie?"

"You're clear – wait, no. You have a swarm of frolions on your tail," responded the computer operator with a fatalistic sigh.

The three began to run.

- - - -

Ulrich, still leading her in macabre imitation of a dance, slowly drew Yumi closer to the speaker, where blue sparks crackled in time to the pulsing club music. The black clad girl darted a glance behind her and, panicking, lashed out with one leg to kick her friend in the stomach. For a second, his grip slackened and she thought she might escape, but she had only freed one hand; next thing she knew, he had ducked her under their arms and brought her back.

"Don't you get it?" XANA scoffed in Ulrich's familiar voice, "You can't beat me. Your friend so obligingly lending me his body can't beat me. You've _lost_, Yumi."

She shook her head vehemently, black hair glistening in the uncertain light. "Not while I'm still breathing. Aelita will deactivate the Tower – you can't stop her."

"But I can," XANA retorted, maddeningly smug.

"And I don't believe Ulrich's beaten either," Yumi hissed defiantly, edging closer to her captor, trying to avoid the speakers, searching for some hint of the boy she knew in those XANA-tainted eyes.

- - - -

Sissi, Aelita, and Kloe pelted along the narrow bridge, a swarm of five green wasps humming along behind them and rapidly gaining. The reporter, tossing a quick glance over her shoulder, began to slow.

"Aelita, Elizabeth, keep going," she panted, "I'll hold them off for as long as I can." A laser whistled past her ear; she ran one hand down the leather bandolier sung across her chest. Eight darts remained.

Aelita gasped a quick assent; the only response of the principal's daughter was, "It's _Si_-si!" Then the frolions closed in.

Kloe launched two darts in quick succession, feeling the novocained almost-pain of a laser strike her ankle. Her efforts to dodge were half-hearted at best; better to run out of life points and devirtualize then to fall off the edge of the precarious bridge and be lost to both worlds. Somehow, she couldn't imagine Jeremie moving heaven and earth to get her back.

The first two darts found their targets, as did the third. The fourth was lost as a laser struck her wrist, skewing her throw sideways. Pulling out another pair, the second-to-last wasp was dispatched, but the final monster was a better marksman, or perhaps just lucky. Its shot took her squarely in the stomach, knocking her down and sending her skidding several feet along the path. She reached into her bandolier as she rose, pulling another dart free. "Life points?" She managed, sighting carefully.

"Uh –" Jeremie watched her virtual figure blink red on his computer screen. "Just get that last wasp."

Too late; the monster fired again, and the red-coated reporter dissolved into fluttering blue squares.

The bug buzzed onward, towards the end of the bridge.

Aelita and Sissi had made it to where the bridge joined with the path spiraling up the stone pinnacle and turned onto the ramp without breaking stride, both breathing heavily. The Tower was visible above them if either craned their necks, red and malevolent. Not quite so far ahead –

"Tarantules," said Jeremie, "About halfway up the ramp, a pair of them. And one of the wasps is still tailing you."

"Any sign of a scipazoa?" Aelita gasped.

Jeremie obligingly checked his screen. "Not yet."

Around the constant curve of the path, a sleek, white silhouette appeared. Four legs carried it swiftly and surely down the spiral ramp, leaving two arms free, trained on Sissi, and firing rapidly. A second was visible behind it, not yet shooting. Over the zing of laser fire, the hum of an approaching frolion's wings was faint, but Sissi heard it, rapidly growing louder. "What are we going to do?" Begged the principal's daughter.

"Get in the back," said Aelita, pressing herself against the rock. "They won't fire on me."

Sissi looked as though she wanted to question this, but managed to restrain herself, quietly sidling around Aelita. "I don't know if this is such a good idea," Jeremie warned, but Aelita had already stepped forward around the curve of the path, in full view of the tarantules. Firing immediately ceased.

The wasp came buzzing up the path, perhaps expecting only Aelita. At any rate, it seemed as surprised as a mechanical monster can seem when Sissi leapt up in front of it, slicing down with two pink-wreathed hands to end its virtual existence.

"Okay," said Jeremie, "Now the tarantules."

"…Tarantules? How come I never get to fight the cool monsters?" It was Kloe's voice, getting louder as she walked closer to Jeremie and his microphone.

"You will, if this lasts long – oh, no," Jeremie interrupted himself.

"What?" said Aelita and Sissi together. They were both clinging to the stone spire as the tarantulas considered them, not daring to move forward or back.

"There's a scipazoa coming up behind you," Jeremie announced gloomily.

"We've got to get through," Aelita declared.

"Right," said Sissi, trying to look bold, "Let me through." She carefully passed in front of Aelita, took a deep breath, and charged the first tarantule. "Bansai!"

In her credit, she managed to take out the first, but tarantulas have much better aim then krabes.

Jeremie pounded the desk beside his keyboard as the triangle representing Sissi winked off the map. "No, no, no!"

Aelita took a step forward, knowing it was hopeless. The tarantule merely shifted, completely blocking the narrow path. Slowly, so slowly, the elf looked behind her. A great, ghostly form was traveling upwards, sedate and calm as the jellyfish it resembled drifting towards helpless prey…

- - - -

Ulrich edged Yumi closer to the speakers again. She had bought herself some time, but not enough, and the electric buildup was enough to make her hair stand on end. Even if she survived the initial jolt, XANA was right there, smugly confident, waiting to finish her off.

"Ulrich," she tried again, "I know you can beat this."

She thought she saw something flicker, deep in his eyes, but XANA only smiled. "Has anyone ever told you how tiresome you are? All of you. So hopelessly defiant," he chided, shoving her towards the speaker.

The final beat of the song shuddered through the soles of her feet, and there was a momentary pause, that brief gap between tracks. Ulrich dipped her, still maintaining the parody of a dance, but she pulled herself up towards him, one last futile gesture, had to bring Ulrich back - looped her arm around his neck to pull him closer, and kissed him.

- - - -

In Lyoko, the Tower winked out.

"Huh?" Jeremie gasped.

"What?" Aelita breathed, backing away from the scipazoa. Her foot met empty air; she realized she was standing on the edge of the path.

"Of course!" Jeremie exclaimed, then, "I'm pulling you out!" He brought up the materialization program, fully loaded now, and hit 'execute.'

- - - -

Yumi pulled back from Ulrich, slowly opening her eyes. He was watching her with the weary gaze of one who has just fought an exhausting battle, but his own eyes were free of XANA's symbol.

The electricity crackling through the speakers faded away. Yumi sagged back against the box, heedless of the vibrations of a new song starting. "Ulrich. You did it."

"Couldn't have done it without you." The cliché was imbued with such sincerity he might have been the first person to say it. "I…"

For a moment, they stood, saying nothing. The music rose. Suddenly, the thought striking her from the ether, Yumi shouted: "Oh, no. We have to find Odd and get to the Factory!"

Ulrich merely nodded, things left unsaid once more, a moment that could have changed everything going unacknowledged; they would soon be trying to forget it. Right now, there were more pressing problems; their purple-clad friend was not behind the tape deck, nor could the DJ recall where he'd gone.

- - - -

Jeremie let his head fall forward onto the keyboard as Kloe and Sissi looked on. "Jeremie?" Came Aelita's voice from the scanner room, "What's going on? What about the Tower."

"It deactivated," Jeremie said happily into his keyboard.

The elevator doors opened, and Odd stepped out, hair a little frizzier then normal but otherwise fine. "Need a hand?" He squeaked.

"Actually, I think we're done here," said Jeremie, lifting his head, "As far as I can tell, Ulrich must have fought off the virus – that's the only thing that makes sense."

"Mm," said Odd, "Well, in that case…" he extended a hand to Sissi. "I believe we're missing a dance?"

- - - -

The DJ was packing up his equipment by the time Odd left. The others had lingered as well; Jeremie and Aelita, Ulrich and Yumi, Sissi, and Kloe, complaining melodramatically that William had abandoned her.

They walked out as a group into the chill, starry night. Jeremie was giving another animated lecture. "So once I've done a scan of Ulrich, I can isolate the 'antibodies' produced against XANA." Ulrich and Yumi exchanged glances; they hadn't told the _entire_ story of what had happened at the dance.

"Great," said Odd, "How about Sissi? And Kloe."

"Well," began the computer geek, "I think you can see why this has to be a secret, so-"

"Rule of ten," Kloe interrupted.

"What?"

"Rule of ten. Up to ten people can keep a secret before it isn't a secret anymore. Sissi and I make seven." She crossed her arms over her chest, daring him to contradict her.

Jeremie sigh. "Well, I think Aelita's antivirus is more important then anything else right now."

Kloe smiled a triumphant smile. Odd slung an arm over Sissi's shoulder, which she promptly shrugged off. "Welcome to the group!"

For a short while, they walked in silence. Then Odd spoke up again. "By the way, weird coincidence, but – after I left the dance? I was pretty sure I passed William on the bridge to the Factory."

– Fin –


End file.
